This project is devoted to detailed analysis of pyridoxal enzyme systems using advanced instrumental analytical techniques. The initial objective is three fold: 1) to investigate the usefulness of low temperature luminescence and photo excited EPR spectroscopy in studies of pyridoxal systems, 2) to develop and extend the system of computerized instrumentation to be used, and 3) to investigate the details of the catalytic mechanism of the pyridoxal-copper enzyme, hog kidney diamine oxidase. The low temperature fluorescence and phosphorescence of pyridoxal compounds has not yet been exploited as an analytical tool for studies of pyridoxal enzymes. Several features of these measurements suggest their utility. Of even more interest, however is the electron paramagnetic resonance signal associated with the photoexcited triplets of these compounds. Using these and other spectroscopic tools such as stopped-flow spectroscopy, difference spectroscopy, and polarization of fluorescence spectroscopy along with the power of the computer instrument systems to correlate and manipulate a variety of data, the sequence of reaction events and the role of copper in diamine oxidase will be investigated.